1. Field of the Invention
The present invention relates generally to a mobile communication system, and in particular, to a method of continuously transmitting user data on a reverse common channel in a mobile communication system.
2. Description of the Related Art
The third generation (3G) IS-95 supports multiple data services in addition to standard voice services including: transmission of high quality voice, high speed data, moving pictures, and internet browsing. In this mobile communication system, a forward link is directed from a base station (BS) to a mobile station (MS) and a reverse link is directed from the MS to the BS. A paging channel and an access channel, generally referred to as common channels, are used to transport data between a BS 4 and an MS 2 before a voice call set-up, as shown in FIG. 10. The BS 4 sends a message on the paging channel and receives a response message from the MS 2 on the access channel. The MS 2 sends a message on the access channel and receives a response message from the BS 4 on the paging channel. A plurality of paging channels and access channels are available for use. The paging channels are typically modulated by Walsh codes and the access channels are modulated by Long codes.
The 3G IS-95 is satisfactory for voice communications but fails to fully ensure high communication quality for packet data communication, where a large amount of packet data including a long burst period and an idle period is transmitted by an RLP (Radio Link Protocol) and short burst data is transmitted by an RBP (Radio Burst Protocol). RBP is a transmission scheme for determining whether to retransmit the same SDB (Short Data Burst) frame or to send another SDB frame depending on an acknowledgement signal (ACK) or negative acknowledgement signal (NACK) received for the previously sent SDB frame in a dormant burst state of the 3G IS-95.
Thus, in the 3G IS-95 system, the RBP has relatively low transmission efficiency, reliability and long response time, since the RBP is confined to a burst substate of the dormant state. Further, since the RBP is implemented on a burst substate of the dormant state with reverse common channel only, the process of sending an SDB frame, receiving a response, and then sending another SDB frame takes a long time, thus causing excessive delay in effecting packet data communications.
It is, therefore, an object of the present invention to provide a method of continuously transmitting a long burst message on a reverse common channel.
It is another object of the present invention to provide a method of implementing a full-duplex RBP transmission scheme in which an SDB message is continuously transmitted on a reverse common channel in a burst substate of the dormant state.
It is a further object of the present invention to provide a method of enabling a long burst message transmission when power control is performed on a designated reverse common channel to appropriately control an initial system access power to minimize response time and increase transmission efficiency.
It is still a further object of the present invention to provide a method of continuously transmitting burst data without initializing an RLP by setting a control channel from a dormant state or a suspended state to a control hold state or an active state.